This blog is aimed at those of you who may do lots of lifting day to day – be it lifting boxes at work, bricks on a building site, weights in the gym or even just lifting your kids up in the evening. We all do it but are we doing it properly?
You’ve all heard of the phrase ‘bend with your knees, not with your back’, but if I ask someone do they lift properly when they pick up heavy items, they usually are the first to admit that they don’t lift correctly and are well aware of it. So the question is – why do they keep doing it? Maybe a lot of you aren’t aware of what’s going on underneath or the potential risk of injury.
Our bodies are very well adapted to a variety of tasks, but we need to be careful not to take advantage of this and push our bodies to breaking point! So let me talk you through the art of lifting.
As a lot of you are well aware, the spine is made up of individual bones called vertebrae, each separated by a shock absorbing disc. Discs are composed of a tough, fibrous tissue on the outside (annulus fibrosis) and a watery, gelatinous material on the inside (nucleus pulposus) – a similar arrangement to a jam doughnut. They need to be quite flexible to allow for normal spinal movement, such as flexion, extension, bending, rotating, etc.
The spine should sit in a shallow ‘S’ shape – this allows the weight of the body to be evenly distributed throughout the discs in the spine. The spine (and the lower back in particular relevance to lifting) also has a lot of strong stabilising structures, both passive and active. Passively, it has lots of non-elastic ligaments holding things in place, but more actively it has musculature stabilisation – or more commonly known as your core.
These muscles are called your core muscles for a reason – they have three-dimensional depth and functional movement in all planes of motion, hence making up the stabilising ‘core’ of our bodies.
So what happens when I lift?
Now we’ve been over the anatomy, let’s talk about how it works when you lift. Normally when we bend down to do something, we tend to bend from the back keeping our legs relatively straight. Why do we do this? Of course – because it’s comfortable and saves energy! But it results in flexion into the lower back, which combined with the load that you lift can put serious amount of stress onto the intervertebral discs, the surrounding muscles, ligaments and joints of the spine. Let’s talk about what can happen each of these areas.
As I mentioned previously, discs are tough on the outside but jelly like on the inside. Discs are designed to take weight straight through their centre, so just imagine their anatomy when you’re bending forward – all the weight goes on the front part of the disc, which pushes the nucleus pulposus to the back of the disc. If the pressure is significant enough, or if the discs happen to be weakened from a long-standing history of increased pressure on the disc, then the nucleus pulposus can bulge out the back of the disc, or even worse break the disc open and sequester out.
This can lead to pressure on the spinal cord or on the nerves where they exit the spinal column, leading to pain, tingling, numbness or weakness down one or both legs. Disc injuries can be very problematic and can often take a long time to heal.
Secondly, muscles are similar to discs in the fact that they don’t like too much stress being placed on them. Muscles are designed to be versatile, obviously as they allow us to do so much with our bodies, however they do have their limits. Imagine holding a weight/bowling ball in close to your chest – it’s relatively easy to do this right? Now if you extend your arms forward and then try to hold the weight, your arms may start to shake and suddenly it becomes more difficult to support the weight and you don’t feel so strong.
The same goes for your muscles – if they are supporting your body weight when your vertebrae are stacked nicely on top of each other in a neutral spine position, it’s easy for them to brace and support your weight, but if you’re bending forward this shifts your centre of gravity forward, making those muscles have to work up to 4 times harder to support your weight.
So it’s no wonder lifting with a bent back can cause muscle strains quite easily is it?! A strain is when some of the muscle fibres become partially torn, which often results in inflammation and muscle spasms, and can be very debilitating.
Ligaments & Joints
Lastly, the more ‘passive’ structures can also become injured from incorrect lifting techniques. Ligaments can become sprained, ie. stretched too far or torn from bending forward while lifting or twisting.
Ligaments are very strong structures so usually take more significant trauma to cause damage, however years of slouching or poor posture can take a toll and cause ligaments to become stretched and weakened so they cannot properly control our joints, hence predisposing them to becoming injured more easily during activities like lifting.
Joints can easily become ‘locked’ or stiffen up from incorrect technique, as again it places excess stress onto them. As a result, they can become dysfunctional – not moving as properly as they should do, which leads to feelings of stiffness or achiness.
So how can I prevent these problems from happening?
Basically, we need to keep pressure evenly distributed throughout our discs when we lift, allowing the ligaments to not be stressed and the surrounding muscles able to perform at their best to support the spine. This can be done by maintaining a neutral spine position; a very slight concave curve in the lower back, braced by the surrounding muscles, and bending down into a shallow squat position to lift things up.
Keep your head and shoulders directly above your waist, and your feet slightly apart. Try not to twist when lifting – this overloads one side more than the other and increases your risk of injury. Try to keep the weight in closer to your body, keeping your centre of gravity more central. Check out this video from the British Chiropractic Association which shows you how it’s done.
So there you have it. Now that you’re more aware of the potential injuries that can result from lifting, it might make you think twice before lifting something heavy with a bent back! If you have had an injury from lifting, get in touch with one of our chiropractors to talk about it, or come in for a consultation. Whatever you are lifting from day to day, remember – Lifting’s a breeze when you bend at the knees!